Section 4. Hearing Protection and Hearing Conservation Program (WAC 296-817-200), Noise Level Survey Contents 4.1 Hearing Conservation Program... 4-1 4.1.1 Intensity and Duration... 4-1 4.1.2 How the Ear Works... 4-2 4.1.3 Warning Signs... 4-2 4.2 Monitoring... 4-2 4.2.1 Noise Exposure... 4-2 4.2.2 Engineering Controls... 4-2 4.2.3 Supervisor Responsibilities... 4-2 4.3 Hearing Protection Devices... 4-2 4.3.1 Ear Muffs... 4-2 4.3.2 Foam Ear Plugs... 4-3 4.4 Annual Hearing Tests... 4-3 4.5 Recordkeeping... 4-3 4.6 Noise Level Survey... 4-3 4.6.1 How to Use the Chart... 4-3 4.6.2 Noise Level Survey Chart... 4-4 4.7 Noise Exposure with Hearing Protection... 4-5 4.1 Hearing Conservation Program Hearing loss is not, and should not be considered, an inevitable part of your job or a natural part of aging. With proper hearing protection, both on and off the job, your hearing can last your entire lifetime. The TFREC has implemented the hearing conservation program to aid in preventing hearing loss from noise exposure. The hearing conservation goal is to identify employees whose job duties may expose them to noise greater than an average of 85 db and provide these employees with hearing protection, training and annual hearing tests. 4.1.1 Intensity and Duration The amount of damage from noise depends upon two factors: the intensity of the noise, measured in decibels (db), and the duration of exposure. Sounds above 130 db are painful and most people will avoid these noise levels. However, sounds between 85 and 120 db may not cause physical pain, but they will damage hearing over time. TFREC Occupational Illness and Injury Prevention Plan SECTION 4: Hearing Protection, Page 4-1
4.1.2 How the Ear Works In order to understand how noise causes hearing loss, one needs to understand how the ear works. Sound waves cause the eardrum to vibrate. These vibrations pass through three tiny bones in the middle ear and on to the hair cells in the fluid-filled inner ear. The vibrations of the hair cells are transmitted as nerve impulses to the brain which are translated as sound. Loud noise damages the hair cells and, therefore, eliminates the nerve impulse to the brain. 4.1.3 Warning Signs Early signs of hearing loss may include tinnitus, or ringing in the ear, temporary muffled hearing, an inability to hear high-pitched noises such as children s voices, inability to hear soft sounds or an inability to distinguish one word from another. 4.2 Monitoring Employees' noise exposure is determined through noise monitoring. Work areas should be tested if you have to raise your voice to be heard two feet away. A copy of noise monitoring performed at the TFREC is provided with this plan. If you feel other equipment or areas should be included in the noise-monitoring program, contact Jerry Moreland. 4.2.1 Noise Exposure With this noise monitoring data, determinations are made regarding job positions with a time weighted average noise exposure of 85 db or more. These positions will be included in the hearing conservation program. Employees must be notified if the sound levels in their work areas exceed 85 db. 4.2.2 Engineering Controls Noise levels can be minimized by engineering controls such as using sound barriers to isolate noisy equipment from the work environment, by administrative controls such as limiting the time an employee is exposed to loud noises, or by personal hearing protection devices. The noise monitoring data should be used to determine when personal hearing protection should be used. Though not required by law, it would be prudent to wear hearing protection for all exposures above 85 db regardless of the time exposed. Signs will be placed at the entrance to work areas where the decibel reading is 115 or over. Hearing protection must always be worn in these areas. 4.2.3 Supervisor Responsibilities Supervisors must determine which activities in their program will require hearing protection. The supervisor should also help the employee select and effectively use proper hearing protection. The employer must provide personal hearing protection devices at no cost to the employee. 4.3 Hearing Protection Devices Hearing protection devices must fit properly in order to be effective. Listed below are some guidelines for proper fit for various types. 4.3.1 Ear Muffs Cups should fully enclose the entire ear without resting on the ear. The headband should sit comfortably on the head. Head gear must not interfere with the seal. TFREC Occupational Illness and Injury Prevention Plan SECTION 4: Hearing Protection, Page 4-2
If fit is correct, a noticeable difference in sound level should detected between when the muffs are off or on. Use the same sound check on each ear. 4.3.2 Foam Ear Plugs Roll plugs into a crease-free cylinder. Pull outer ear upwards and outwards. Insert properly rolled plug into ear. Maintain pressure on the plug until it expands in the ear canal. To check proper fit, put hands over ears. There should be little change in sound level if your hands are on or off your ears. If properly inserted the plug should be crease- and wrinkle-free when removed and the compressed portion should be at least half of the plug. 4.4 Annual Hearing Tests Annual hearing tests will be provided to all employees determined to have time weighted exposure to sound levels averaging 85dB or above. If testing demonstrates a continued loss of hearing in an individual, then the supervisor must re-evaluate the work environment of the employee, must re-evaluate the type and proper fit of the hearing protection the employee is using, and must ensure that the employee does wear hearing protection when required. At the time of hire and annually thereafter, training will be provided to each employee having an average noise level exposure of 85 db or above. 4.5 Recordkeeping Records of noise exposure measurements, hearing protection training, and audiometric testing must be maintained by the employer and available to the employee. 4.6 Noise Level Survey The noise survey chart details employee noise exposure without hearing protection and is set up to enable supervisors to determine if employees in their program should be in a hearing conservation program. 4.6.1 How to Use the Chart If, for example, a supervisor wanted to know if an employee who operates the John Deere mower should be in the hearing conservation program they could refer to the exposure column for that piece of equipment and if the employee operated the mower more than 4 hours per day then the employee should be in the hearing conservation program. If the % dose is over 50% or if the TWA is 85dB or more for the number of hours indicated then the employee should be included in the hearing conservation program. TFREC Occupational Illness and Injury Prevention Plan SECTION 4: Hearing Protection, Page 4-3
4.6.2 Noise Level Survey Chart Completed 8/99 with Quest Q-400 Noise Dosimeter (dosimeter calibrated before and after each use according to manufacturer's directions). EQUIPMENT MAX AVG Exposure (hr) %DOSE TWA* OVERLEY BUILDING #4 growth chamber 79 #3 growth chamber 79 #1 growth chamber 80 66 #2 growth chamber 92 88 6 56.6% 85.8 db Supply fan #1 86 85 8 50% 85 db Air Conditioning Compressor 94 90 4 50% 85 db Refrigeration compressor room 88 87 7 57.9% 86 db Cooling tower 81 Autoscrubber 81 Burnisher 83 BOILER ROOM Boiler Room 108 83 8 37.9% 82.6 db USDA BUILDING Chiller 88 82 8 32.9% 81.5 db Refrigeration compressor room 86 83 8 37.9% 82.6 db Near growth chambers 83 Machine room 82 Walk-in cold rooms 79 SHOP Arc welder 89 87 7 57.9% 86 db Air Compressor 87 82 8 32.9% 81.5 db Garage door opener 105 102 3/4 50% 85 db Background noise 78 74 Vehicle engine noise 75 Fork lift 70 Metal chop saw 112 107.38 50% 85 db Table saw 115 109.29 50% 85 db Radial arm saw 123 107 FARM AND GROUNDS Kubota 5400 with sprayer 87 86 7 50.4% 85.1 db Weed Eater 94 92 4 64.5% 86.9 db Blower 99 96 2 57.1% 85.9 db John Deere mower 97 90 4 50% 85 db Snow Blower 108 97 1.5 50% 85 db Lawn edger 90 86 7 50.4% 85.1 db Massey Ferguson 135 94 89 5 54.3% 85.6 db with Parker sprayer (self-powered) 102 101 1 58.8% 86 db Landini Tractor no implements 96 91 4 57.1% 85.9 db Landini with Air-O-fan sprayer 98 91 4 57.1% 85.9 db TFREC Occupational Illness and Injury Prevention Plan SECTION 4: Hearing Protection, Page 4-4
EQUIPMENT MAX AVG Exposure (hr) %DOSE TWA* Large Cat.(army surplus) 103 100 1 50% 85 db Gyrette 93 88 6 56.6% 85.8 db Chain saw 103 101 1 58.8% 86 db Massey Ferguson 2135 98 91 4 57.1% 85.9 db MF 2135 with John Deere 509 98 93 3 56.6% 85.8 db Craftsman Lawn mower 98 92 4 64.5% 86.9 db Keith's ATV 102 71 John Deere 2350 Tractor 95 90 4 50% 85 db J.D.2350 with Woods Mower 100 92 4 64.5% 86.9 db Pathology truck mounted sprayer 112 94 2.3 50% 85 db * TWA for hours in column 3 4.7 Noise Exposure with Hearing Protection The following chart lists noise exposure for varying decibel levels and time durations with hearing protectors that have a listed noise reduction rating (NRR) of 29. Hours Exposed Decibel level 4 5 6 7 8 85 58 59 61 62 63 90 63 64.5 66 67 68 95 68 70 71 72 73 100 73 74.6 75.9 77 78 110 83 84.7 * * * * Above permissible exposure level. TFREC Occupational Illness and Injury Prevention Plan SECTION 4: Hearing Protection, Page 4-5